-
Journal of Clinical Monitoring and... Aug 2023Over the past few years, the use of non-invasive neuromonitoring in non-brain injured patients has increased, as a result of the recognition that many of these patients... (Review)
Review
Over the past few years, the use of non-invasive neuromonitoring in non-brain injured patients has increased, as a result of the recognition that many of these patients are at risk of brain injury in a wide number of clinical scenarios and therefore may benefit from its application which allows interventions to prevent injury and improve outcome. Among these, are post cardiac arrest syndrome, sepsis, liver failure, acute respiratory failure, and the perioperative settings where in the absence of a primary brain injury, certain groups of patients have high risk of neurological complications. While there are many neuromonitoring modalities utilized in brain injured patients, the majority of those are either invasive such as intracranial pressure monitoring, require special skill such as transcranial Doppler ultrasonography, or intermittent such as pupillometry and therefore unable to provide continuous monitoring. Cerebral oximetry using Near infrared Spectroscopy, is a simple non invasive continuous measure of cerebral oxygenation that has been shown to be useful in preventing cerebral hypoxemia both within the intensive care unit and the perioperative settings. At present, current recommendations for standard monitoring during anesthesia or in the general intensive care concentrate mainly on hemodynamic and respiratory monitoring without specific indications regarding the brain, and in particular, brain oximetry. The aim of this manuscript is to provide an up-to-date overview of the pathophysiology and applications of cerebral oxygenation in non brain injured patients as part of non-invasive multimodal neuromonitoring in the early identification and treatment of neurological complications in this population.
Topics: Humans; Cerebrovascular Circulation; Oximetry; Monitoring, Physiologic; Brain; Brain Injuries; Nervous System Diseases
PubMed: 37043157
DOI: 10.1007/s10877-023-01002-8 -
Journal of Biomedical Optics Jun 2024Photoacoustic imaging (PAI) promises to measure spatially resolved blood oxygen saturation but suffers from a lack of accurate and robust spectral unmixing methods to...
SIGNIFICANCE
Photoacoustic imaging (PAI) promises to measure spatially resolved blood oxygen saturation but suffers from a lack of accurate and robust spectral unmixing methods to deliver on this promise. Accurate blood oxygenation estimation could have important clinical applications from cancer detection to quantifying inflammation.
AIM
We address the inflexibility of existing data-driven methods for estimating blood oxygenation in PAI by introducing a recurrent neural network architecture.
APPROACH
We created 25 simulated training dataset variations to assess neural network performance. We used a long short-term memory network to implement a wavelength-flexible network architecture and proposed the Jensen-Shannon divergence to predict the most suitable training dataset.
RESULTS
The network architecture can flexibly handle the input wavelengths and outperforms linear unmixing and the previously proposed learned spectral decoloring method. Small changes in the training data significantly affect the accuracy of our method, but we find that the Jensen-Shannon divergence correlates with the estimation error and is thus suitable for predicting the most appropriate training datasets for any given application.
CONCLUSIONS
A flexible data-driven network architecture combined with the Jensen-Shannon divergence to predict the best training data set provides a promising direction that might enable robust data-driven photoacoustic oximetry for clinical use cases.
Topics: Photoacoustic Techniques; Oximetry; Humans; Neural Networks, Computer; Oxygen; Oxygen Saturation; Algorithms
PubMed: 38841431
DOI: 10.1117/1.JBO.29.S3.S33303 -
Frontiers in Digital Health 2023Smartphone camera photoplethysmography (cPPG) enables non-invasive pulse oximetry and hemoglobin concentration measurements. However, the aesthetic-driven non-linearity...
Smartphone camera photoplethysmography (cPPG) enables non-invasive pulse oximetry and hemoglobin concentration measurements. However, the aesthetic-driven non-linearity in default image capture and preprocessing pipelines poses challenges for consistency and transferability of cPPG across devices. This work identifies two key parameters-tone mapping and sensor threshold-that significantly impact cPPG measurements. We propose a novel calibration method to linearize camera measurements, thus enhancing consistency and transferability of cPPG across devices. A benchtop calibration system is also presented, leveraging a microcontroller and LED setup to characterize these parameters for each phone model. Our validation studies demonstrate that, with appropriate calibration and camera settings, cPPG applications can achieve 74% higher accuracy than with default settings. Moreover, our calibration method proves effective across different smartphone models (), and calibrations performed on one phone can be applied to other smartphones of the same model (), enhancing consistency and scalability of cPPG applications.
PubMed: 38075521
DOI: 10.3389/fdgth.2023.1301019 -
Journal of the American Heart... Jun 2024
-
Clinical Chemistry and Laboratory... Sep 2023Human blood gas stability data is limited to small sample sizes and questionable statistical techniques. We sought to determine the stability of blood gases under room...
OBJECTIVES
Human blood gas stability data is limited to small sample sizes and questionable statistical techniques. We sought to determine the stability of blood gases under room temperature and slushed iced conditions in patients using survival analyses.
METHODS
Whole blood samples from ∼200 patients were stored in plastic syringes and kept at room temperature (22-24 °C) or in slushed ice (0.1-0.2 °C) before analysis. Arterial and venous O (15-150 mmHg), CO (16-72 mmHg), pH (6.73-7.52), and the CO-oximetry panel [total hemoglobin (5.4-19.3 g/dL), percentages of oxyhemoglobin (OHb%, 20-99%), carboxyhemoglobin (COHb, 0.1-5.4%) and methemoglobin (MetHb, 0.2-4.6%)], were measured over 5-time points. The Royal College of Pathologists of Australasia's (RCPA's) criteria determined analyte instability. Survival analyses identified storage times at which 5% of the samples for various analytes became unstable.
RESULTS
COHb and MetHb were stable up to 3 h in slushed ice and at room temperature; CO, pH was stable at room temperature for about 60 min and 3 h in slushed ice. Slushed ice shortened the storage time before O became unstable (from 40 to 20 min), and the instability increased when baseline O was ≥60 mmHg. The storage time for O, CO, pH, and CO-oximetry, when measured together, were limited by the O.
CONCLUSIONS
When assessing O in plastic syringes, samples kept in slushed ice harm their stability. For simplicity's sake, the data support storage times for blood gas and CO-oximetry panels of up to 40 min at room temperature if following RCPA guidelines.
Topics: Humans; Ice; Temperature; Oximetry; Blood Gas Analysis; Plastics; Gases; Oxygen; Carbon Dioxide; Hydrogen-Ion Concentration
PubMed: 37015069
DOI: 10.1515/cclm-2022-1085 -
JAMA Network Open Aug 2023Approximately 8% of acute pulmonary emboli are confined to the subsegmental arteries. The 2016 and 2021 American College of Chest Physicians (CHEST) guidelines and...
IMPORTANCE
Approximately 8% of acute pulmonary emboli are confined to the subsegmental arteries. The 2016 and 2021 American College of Chest Physicians (CHEST) guidelines and expert panel reports suggest the use of structured surveillance without anticoagulation for select ambulatory patients with subsegmental pulmonary embolism who do not have active cancer, deep vein thrombosis, impaired cardiopulmonary reserve, marked symptoms, or increased risk of recurrent venous thromboembolism; however, guideline uptake in community practice is unknown, as is the proportion of outpatients eligible for surveillance.
OBJECTIVE
To describe the prevalence of surveillance among outpatients with acute subsegmental pulmonary embolism and to estimate the proportion of patients eligible for structured surveillance using modified CHEST criteria.
DESIGN, SETTING, AND PARTICIPANTS
This retrospective cohort study was conducted across 21 US community hospitals in the Kaiser Permanente Northern California integrated health system from January 1, 2017, to December 31, 2021. Adult outpatients with acute subsegmental pulmonary embolism were included. Patients with the following higher-risk characteristics were excluded: codiagnoses requiring hospitalization, non-low-risk vital signs (ie, systolic blood pressure <90 mm Hg, pulse ≥110 bpm, or peripheral cutaneous pulse oximetry ≤92%), prediagnosis anticoagulant use, or hospice care. Data analysis was performed from November 2022 to February 2023.
MAIN OUTCOMES AND MEASURES
The main outcomes were the (1) prevalence of surveillance and (2) eligibility for surveillance using 2 sets of criteria: the CHEST criteria modified by excluding patients with higher-risk characteristics or right ventricular dysfunction and a stricter set of criteria requiring age younger than 65 years and no more than 1 embolus. The prevalence of structured surveillance was calculated and the proportion of patients eligible for surveillance was estimated.
RESULTS
Of the 666 outpatients with acute subsegmental pulmonary embolism included in this study, 229 with lower-risk characteristics were examined. Their median age was 58 (IQR, 42-68) years; more than half were men (120 [52.4%]) and self-identified as non-Hispanic White (128 [55.9%]). Six patients (2.6%) were initially not treated with anticoagulants. Among the lower-risk cohort, only 1 patient (0.4% [95% CI, 0.01%-2.4%]) underwent structured surveillance, without 90-day sequelae. Thirty-five patients (15.3% of the lower-risk group and 5.3% of the full cohort) were surveillance eligible using modified CHEST criteria. Fifteen patients (6.6% of the lower-risk group and 2.3% of the full cohort) were surveillance eligible using stricter criteria.
CONCLUSIONS AND RELEVANCE
In this cohort study of lower-risk outpatients with subsegmental pulmonary embolism, few were eligible for structured surveillance, and only a small proportion of eligible patients underwent surveillance despite the CHEST guideline. If forthcoming trials find surveillance safe and effective, substantial uptake into clinical practice may require more than passive diffusion.
Topics: Male; Humans; Adult; Middle Aged; Aged; Female; Cohort Studies; Retrospective Studies; Prevalence; Treatment Outcome; Anticoagulants; Pulmonary Embolism
PubMed: 37531107
DOI: 10.1001/jamanetworkopen.2023.26898 -
Cancer Immunology Research Oct 2023Infiltration of tumor by T cells is a prerequisite for successful immunotherapy of solid tumors. In this study, we investigate the influence of tumor-targeted radiation...
Infiltration of tumor by T cells is a prerequisite for successful immunotherapy of solid tumors. In this study, we investigate the influence of tumor-targeted radiation on chimeric antigen receptor (CAR) T-cell therapy tumor infiltration, accumulation, and efficacy in clinically relevant models of pleural mesothelioma and non-small cell lung cancers. We use a nonablative dose of tumor-targeted radiation prior to systemic administration of mesothelin-targeted CAR T cells to assess infiltration, proliferation, antitumor efficacy, and functional persistence of CAR T cells at primary and distant sites of tumor. A tumor-targeted, nonablative dose of radiation promotes early and high infiltration, proliferation, and functional persistence of CAR T cells. Tumor-targeted radiation promotes tumor-chemokine expression and chemokine-receptor expression in infiltrating T cells and results in a subpopulation of higher-intensity CAR-expressing T cells with high coexpression of chemokine receptors that further infiltrate distant sites of disease, enhancing CAR T-cell antitumor efficacy. Enhanced CAR T-cell efficacy is evident in models of both high-mesothelin-expressing mesothelioma and mixed-mesothelin-expressing lung cancer-two thoracic cancers for which radiotherapy is part of the standard of care. Our results strongly suggest that the use of tumor-targeted radiation prior to systemic administration of CAR T cells may substantially improve CAR T-cell therapy efficacy for solid tumors. Building on our observations, we describe a translational strategy of "sandwich" cell therapy for solid tumors that combines sequential metastatic site-targeted radiation and CAR T cells-a regional solution to overcome barriers to systemic delivery of CAR T cells.
Topics: Humans; Mesothelin; Immunotherapy, Adoptive; GPI-Linked Proteins; Receptors, Antigen, T-Cell; Mesothelioma; Mesothelioma, Malignant; Receptors, Chemokine; Chemokines; Cell Line, Tumor
PubMed: 37540803
DOI: 10.1158/2326-6066.CIR-22-0840 -
Children (Basel, Switzerland) Dec 2023Newborns with a critical congenital heart disease left undiagnosed and untreated have a substantial risk for serious complications and subsequent failure to thrive.... (Review)
Review
BACKGROUND
Newborns with a critical congenital heart disease left undiagnosed and untreated have a substantial risk for serious complications and subsequent failure to thrive. Prenatal ultrasound screening is not widely available, nor is postnatal echocardiography. Physical examination is the standard for postnatal screening. Pulse oximetry has been proposed in numerous studies as an alternative screening method. This systematic review and meta-analysis aims to determine the diagnostic accuracies of both screening methods separately and combined.
METHODS
A systematic literature search of the Embase, PubMed, and Global Health databases up to 30 November 2023 was conducted with the following keywords: critical congenital heart disease, physical examination, clinical scores, pulse oximetry, and echocardiography. The search included all studies conducted in the newborn period using both physical examination and pulse oximetry as screening methods and excluded newborns admitted to the intensive care unit. All studies were assessed for risk of bias and applicability concerns using the QUADAS-2 score. The review adhered to the PRISMA 2020 statement guideline.
RESULTS
Out of 2711 articles, 20 articles were selected as eligible for meta-analysis. Cumulatively, the sample included 872,549 screened newborns. The pooled sensitivity of the physical examination screening method was found to be 0.69 (0.66-0.73 (95% CI)) and specificity was found to be 0.98 (0.98-0.98). For the pulse oximetry screening method, the pooled sensitivity and specificity yielded 0.78 (0.75-0.82) and 0.99 (0.99-0.99), respectively. The combined method of screening yielded improved diagnostic characteristics at a sensitivity and specificity of 0.93 (0.91-0.95) and 0.98 (0.98-0.98, respectively.
CONCLUSIONS
The evidence indicates that combining both physical examination and pulse oximetry to screen for critical congenital heart disease exceeds the accuracy of either separate method. The main limitation is that solely newborns with suspected critical congenital heart disease were subjected to the reference standard. We recommend adapting both methods to screen for critical congenital heart diseases, especially in settings lacking standard fetal ultrasound screening. To increase the sensitivity further, we recommend increasing the screening time window and employing the peripheral perfusion index.
PubMed: 38255361
DOI: 10.3390/children11010047 -
Research (Washington, D.C.) 2023Flowing water can be used as an energy source for generators, providing a major part of the energy for daily life. However, water is rarely used for information or...
Flowing water can be used as an energy source for generators, providing a major part of the energy for daily life. However, water is rarely used for information or electronic devices. Herein, we present the feasibility of a polarized liquid-triggered photodetector in which polarized water is sandwiched between graphene and a semiconductor. Due to the polarization and depolarization processes of water molecules driven by photogenerated carriers, a photo-sensitive current can be repeatedly produced, resulting in a high-performance photodetector. The response wavelength of the photodetector can be fine-tuned as a result of the free choice of semiconductors as there is no requirement of lattice match between graphene and the semiconductors. Under zero voltage bias, the responsivity and specific detectivity of Gr/NaCl (0.5 M)W/N-GaN reach values of 130.7 mA/W and 2.3 × 10 Jones under 350 nm illumination, respectively. Meanwhile, using a polar liquid photodetector can successfully read the photoplethysmography signals to produce accurate oxygen blood saturation and heart rate. Compared with the commercial pulse oximetry sensor, the average errors of oxygen saturation and heart rate in the designed photoplethysmography sensor are ~1.9% and ~2.1%, respectively. This study reveals that water can be used as a high-performance photodetector in informative industries.
PubMed: 37529624
DOI: 10.34133/research.0202 -
Children (Basel, Switzerland) Sep 2023Heart rate (HR) is considered the main vital sign in newborns during perinatal transition, with a threshold of 100 beats per minute (bpm), below which, intervention is... (Review)
Review
BACKGROUND
Heart rate (HR) is considered the main vital sign in newborns during perinatal transition, with a threshold of 100 beats per minute (bpm), below which, intervention is recommended. However, recent changes in delivery room management, including delayed cord clamping, are likely to have influenced normal HR transition.
OBJECTIVE
To summarize the updated knowledge about the factors, including measurement methods, that influence HR in newborn infants immediately after birth. Additionally, this paper provides an overview of delivery room HR as a prognostic indicator in different subgroups of newborns.
METHODS
We searched PubMed, EMBASE, and Google Scholar with the terms infant, heart rate, delivery room, resuscitation, pulse oximetry, and electrocardiogram.
RESULTS
Seven studies that described HR values in newborn infants immediately after birth were included. Pulse oximetry-derived HR percentiles after immediate cord clamping may not be applicable to the current practice of delayed cord clamping and the increasing use of delivery room electrocardiograms. Mask ventilation may adversely affect HR, particularly in premature and non-asphyxiated infants. Prolonged bradycardia is a negative prognostic factor, especially if combined with hypoxemia in infants <32 weeks of gestation.
CONCLUSIONS
HR assessment in the delivery room remains important. However, the cardiopulmonary transition is affected by delayed cord clamping, gestational age, and underlying conditions.
PubMed: 37761512
DOI: 10.3390/children10091551